Just wanted to get some opinions on square tubing size to use for my new stand. I plan on modeling it after the sabco system and add the automation later on. Also, it will be made from mild steel. Thanks

not so much the size, but thickness plays more into it,, I would think 1in .135 wall would be strong enough for sure.
the bigger the tubing the thinner the wall can be ie 2in =.095

I have been doing a lot of research myself on the single tier stand! I also purchased the design build (brutus ten) from BYO magazine. They recommend a 2 inch tubing, mostly for support if you plan on mounting the gas lines and liquid lines to the frame(the holes drilled will weaken a thinner tube) And for the thickness they recommend an 11 gauge or .120" I purchased the plans for a local welder and they only cost me $3.00 + shipping. I know its not the sabco design, but its a nice setup!

2 inch tubing @ almost an 1/8" is overkill, imho - unless you are not going to have a center support. I think most designs have a center support (and it makes a great place to mount the pumps to).

Mine is 1/16" X 1.5". Plenty sturdy, and light enough for me to muscle around (with the aid of wheels on two of the legs - a la wheel barrow).


Mylo

Thanks all. I think I am going to go with 1.5 inch just to be on the safe side. The bottom tier frame of the sabco runs the entire length with no support in the middle.

I built a keg stand several years back, decided to bring it into production and now marketing it. I don't think I can post it here, but it's worth looking at. Doesn't take up so much room, and can be made into the system of your choice, HERMS, RIMS etc. We've been brewing for many years with this system, everyone likes it.
I used 1.25 square, 16 GA. (.075) It will handle plenty, casters are good for 250lbs ea. Made for many years of brewing.
The big stands look nice and beefy, but no need to over engineer it, make good beer, and make it fun.

I used the 2" square with .120 walls to build a brutus like stand (shorter and more space between the kettles). With the casters it is easy enough to move around, but I think you would be fine with the next size thinner walls if you were worried about weight. The deciding factor for me was that I was just learning to weld, so the thicker walls would be more forgiving if I ended up being really bad at welding.

I used 2" for the vertical posts and 1" for shelves and the base. It is pretty light and strong.